1. Field of the Invention
The present invention relates to a crayon composition, and especially to one which is washable. The composition is adapted to be made as crayons or pencil leads etc., and is easily washed with water when it has been painted on a cloth or a wall or a smooth surface such as glass surface. The composition is comprised mainly of pigment, polyoxyethylene nonyl phenyl ether, sorbitan monostearate, stearic acid, polyethylene glycol, wax and kaolin, wherein polyoxyethylene nonyl phenyl ether and sorbitan monostearate may be used as stabilizer and surfactant respectively.
2. Description of the Prior Art
The washable crayon compositions available in the market presently are crayon products which are advertised as being easily scrubbed with water after they are painted on a cloth or a wall; however, users are not satisfied with them in practice. For example, a washable solid marking composition as stated in the U.S. Pat. No. 4978390 including polyethylene glycol resin, water soluble surfactant, pigment; at least a compatible viscosity modifier, a compatible plasticizer, an antifoam agent and an inert filler. The molecular weights of the polyethylene glycols used in this composition are all above 10,000. As is known in the art, the higher the molecular weight, the worse the solubility and fluidity thereof, and also the higher the heating temperature for solution thereof and the less uniform the coloration. This can not only induce sensitization of the skin or respiratory tract of a consumer, but it can also create environmental pollution while in the production process.